1. Field of the Invention
The present invention generally relates to a cable connector assembly, and particularly to a cable connector assembly for transmitting high speed signals in an interconnection system.
2. Description of Prior Arts
As the density of interconnects and the transmitting rate of the signals tremendously increase, the close proximity of the contacts in the connectors and the large amount of data with high speed increase the likelihood of strong electrical cross talk coupling between both the contacts and the wires used in the interconnection system. In the case of cables with electromagnetic interference (EMI) shielding, the cable shield is typically coupled to designated contacts in the connectors which are, in turn, coupled to designated terminals in the complementary connectors. Such a ground connection is adequate for most applications, while in the case of high frequency signal, particularly when differential signal pairs are employed in the cables, problems can arise if the transfer impedance and the cross talk are not sufficiently reduced. Shield connections that do not have low enough transfer impedance and cross talk can result in unacceptable high levels of electromagnetic emissions from the cable or unacceptable susceptibility to external sources of electromagnetic radiation.
Ground means are widely used for ground connection of a variety of cable connector assemblies. Such applications of ground means can be found in U.S. Pat. No. 5,522,731 issued to Berg Technology, Inc. on Jun. 4, 1996, U.S. Pat. No. 6,152,754 issued to Masimo Corporation on Nov. 28, 2000, U.S. Pat. No. 6,394,839 issued to Tensolite Company on May 28, 2002, and U.S. Pat. No. 6,203,369 issued to 3M Innovative Properties Company on Mar. 20, 2001.
Hence, a cable connector assembly having a substantial low cross talk and transfer impedance during high rate signal transmission is eagerly required.
Accordingly, an object of the present invention is to provide a cable connector assembly, which has ground plates for substantially reducing cross talk occurred between signal wires of a cable and for particularly reducing cross talk occurred on soldering area where the signal wires are soldered to signal conductive pads of a printed circuit board.
In order to achieve the above-mentioned object, a cable connector assembly in accordance with the present invention is adapted for use with a complementary connector and comprises an electrical connector, a cable having signal wire pairs and drain wires, a spacer attached to the cable and ground plates for grounding purpose. Each ground plate has a soldering portion positioned between the signal wire pairs and conductively connecting with corresponding drain wire. A terminal holder of the electrical connector has a printed circuit board attached to a rear side thereof, which defines a number of first and second conductive pads on opposite surfaces thereof. The ground plates and the drain wires are oppositely arranged on opposite sides of the printed circuit board. The first conductive pads are soldered to terminals of the electrical connector for receiving signals from the complementary connector. The second conductive pads have signal pads soldered to the signal wires of the cable to thereby establish signal paths between the cable and the complementary connector. While, ground pads of the second conductive pads are soldered to the corresponding drain wires and the ground plates to thereby establish first and second ground paths between the cable and the complementary connector.